The flow of blood that exits a man's anus (similar to a menstrual flow). It only occurs once in his life time, and it is the defining moment of his manhood. The flow lasts for 2-3 weeks and the suffering transforms a boy to a man.
When compared to a females period, greep is scientifically proven to be worse. Dr.Schlitterbauhn, part time disney world OB GYN, commented, "on a scale of numb hand to two stubbed toes, greep is around the pain level of whale birth".
"Dude, you are such a child."
"Naw, man. I greeped last week. Im a full man now."
"Damn straight you are"
Noun - A Geeky Creep. A creep whose modus operandi is super geeky (such as the internet).
verb - the act of creeping out in a geeky manner. used in the smae maner as the verb "to creep out"
He was a typical greep. All he ever did was surf the net and create false identities in the hope of finding a hot date. And when he did find someone, he would greep out his victims by spamming their inbox.